Plug

ABSTRACT

A printed-circuit board is formed at a front edge with a cutout. A plug has a base body adapted to fit in the cutout and formed with a pair of shoulders bearing flatly on the board at edges of the cutout. A pair of wing-shaped connecting elements project oppositely from the body and lie flatly on the board adjacent the edges of the cutout so that the elements can be soldered to the board to fix the base body in the cutout.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase of PCT applicationPCT/EP02/13444, filed 28 Nov. 2002, published 5 Jun. 2003 as WO03/047045, and claiming the priority of German patent application10158384.2 itself filed 28 Nov. 2001.

FIELD OF THE INVENTION

The invention relates to a plug with a base body and contact elements inthe interior of the base body.

BACKGROUND OF THE INVENTION

Such plugs are used as electrical connections for electronic devices ofall types in large numbers. In the course of miniaturization of suchdevices, the plugs of the devices are applied directly on the printedcircuit boards upon which the electronic components of such devices arearranged.

The printed circuit boards which can be especially formed of multilayercircuit boards, have a high packing density of their conductive tracksand components. The electronic components are applied to the respectiveprinted circuit boards by means of mounting automatons automatically andare there soldered in place. The production of such assemblies isreferred to as the SMD (Surface Mounting Device) technique.

With this technique at low fabrication cost, complex arrangements ofcomponents on printed circuit boards can be fabricated in arrangementsof relative small size.

It is, however, a problem to integrate plugs in this kind of fabricationprocess. The use of plugs as SMD components is indeed basically known,but the automatic application of such plugs and their connection to theconductors of the printed circuit board is associated with significantdrawbacks because of the relative sizes of such plugs. As a consequence,such plugs are typically soldered by hand to the printed circuit boards,which undesirably increases the fabrication costs of such devices. Afurther significant problem resides in that application of such plugs tothe printed circuit board should be capable of insuring that the unitwhich is thus formed will have the smallest possible size.

OBJECT OF THE INVENTION

The invention has as its object to so form a plug of the type describedat the outset that it can be applied to a printed circuit board in themost rational and space-saving manner possible.

SUMMARY OF THE INVENTION

This object is attained in that the plug has a base body and contactelements which extend into the exterior of the base body. At oppositesides of the outer wall of the base body, two wing-shaped connectorelements open outwardly. These connector elements project over the rearside of the base body whereby their undersides form contact surfaces forproducing solder connections to a printed circuit board. The connectorelements provided on the plug according to the invention serve to enableestablishment of a solder connection with the respective printed circuitboard which forms a ground connection of the plug. Because of the largearea configuration of the contact surface which is seated directly onthe printed circuit board, an especially good ground connection of theplug is obtained.

Furthermore, with the connector elements, good mechanical retention ofthe plug upon the board can be obtained. The plug can thus be positionedon the board by means of an automated mounting machine as an SMDcomponent reliably in a precise position.

Since the connector elements open laterally at the base body of theplug, the base body projects both upwardly and also downwardly beyondthe connector elements. This means that the plug can be mounted on theboard to lie more deeply than plugs have been positioned otherwise sothat the spatial requirements for the plug can be held exceptionallysmall.

The undersides of the connector elements of the plug thus extend in aconnecting plane in which preferably the underside of an internalconductor extending over the back side of the plug also lies. Thisinternal conductor can be soldered together with the contact surfaces ofthe connecting elements to the respective board by means of an automatedsoldering process. This soldering process can be carried out especiallyeffectively in an automated finishing step.

In an especially preferred embodiment, the connector elements closeagainst outer walls in regions of the rear segment of the base body,whereby the rear segments are disposed in a cutout or recess of theboard. The size of the cutout is matched to the shape of the rearsegment. In this manner an especially space-saving application of theplug to the board is achieved. In addition, the plug is positionableprecisely in the cutout and thus is exactly positionable using thecutout on the board. Finally by an appropriate choice of the lengths ofthe connector elements, the plug can be secured upon the board againsttilting since the center of gravity of the plug lies upon the board. Inthis manner dislocation of the plug with respect to the seat upon theboard can be avoided.

A precondition for this aspect of the invention is however a certainminimum length of the connector elements. A greater length of theconnector elements results however in an undesirable increase in theweight of the plug.

In an especially advantageous embodiment of the plug according to theinvention, the base body has shoulders which extend like the connectorelements on oppositely disposed sides of the outer wall of the basebody. The shoulders have bearing surfaces which lie in the sameconnecting plane as the contact surfaces. Preferably the shouldersextend over the entire length of the base body.

During the mounting process, the plug is seated on at least one board,whereby in this case not only the contact surfaces of the connectorelements but also the bearing surfaces of the shoulders lie upon theupper surface of the board. Thus even for the case in which theconnector elements have only a minimum length, a reliable position-exactretention of the plug upon the board on which it is seated can beobtained.

The boards are arranged during the mounting process in multiples forso-called multiple uses. Depending upon the arrangement of the boards,the connecting elements and shoulders of a plug can be caused to restupon one board or upon two mutually abutting boards. In the case inwhich the shoulders and connecting elements rest upon different boardsas a result of the mounting at the edge of the board in which the recessfor receiving the rear segments of the base body is provided, a segmentcan be connected to a second board with additional board material uponwhich the shoulders of the plug mounting upon the first board can rest.This additional board material can serve alone for positionstabilization of the plug during the mounting process and during thesoldering process. After the soldering process has terminated, theadditional board material can be removed from the second board.

BRIEF DESCRIPTION OF THE DRAWING

The invention will be further described based upon the drawings. Theyshow:

FIG. 1 a schematic illustration of an embodiment of a plug according tothe invention mounted upon a printed circuit board.

FIG. 2 a side view of the arrangement according to FIG. 1.

FIG. 3 a cross section through the arrangement according to FIG. 2.

FIG. 4 a plan view of the board according to FIG. 1 without a plug.

SPECIFIC DESCRIPTION

FIGS. 1–3 show an embodiment of the plug 1 according to the inventionwhich is mounted on a printed circuit board 2 as an SMD (SurfaceMounting Device) component. The printed circuit board 2, which, forexample, is constituted as a multilayer board with different conductivepatterns in each layer, has only been shown fragmentarily in the Figuresand in a schematic form. The plug 1 according to the invention or amultiplicity of such plugs 1, are mounted on the board 2 by means of anautomated mounting machine or mounting automaton such that an automatedsoldering connection can also be formed between the boards 2 and theplugs 1.

During this finishing step, the boards 2 are arranged in a multiplearray, so-called multiple use. In FIGS. 1 and 4 the multiple arrangementis signified by two boards 2 and 2 a which border each other and abut attheir longitudinal sides.

The plug 1 has a base body 3 which is comprised as a die cast orinjection-molded part and has a substantially rotation symmetricalconfiguration with respect to its longitudinal axis. In the interior ofthe base body 3 there is an insulator 4 which preferably is comprised ofa plastic. Additional components can also be located in the interior ofthe base body of the plug 1, especially contact elements. One of thecontact elements is formed from an internal conductor 5 which extendsthrough the center of the interior of the base body 3 in itslongitudinal direction and projects beyond the rear side of the basebody 3.

On the upper side of the outer wall of the base body 3 there is locateda detent nose 6 for fixing a socket member on the plug.

In addition on the upper side of the base body 3 there is a recess 7which forms a so-called “pick'n place” surface. On the recess 7 the plug1 can be fitted onto the mounting automaton for gripping thereby toplace the plug 1 upon the board 2. The plug 1 has two wing-shapedconnecting elements 8 which open outwardly on opposite sides of theouter wall of the base body 3. The identically configured connectingelements 8 each have a rectangular contour and are formed in one piecewith the base body 3. The connecting elements 8 have a constantrectangular cross section over their entire lengths.

As is especially visible from FIG. 1, the connecting elements 8 arejoined flushly to rear segments of the base body 3. As a result, frontends of the connecting element 8 project beyond the rear side of thebase body 3.

The planar undersides of the connecting element 8 form contact surfacesand extend in a horizontal connecting plane. In this connecting planethe underside of the inner conductor 5, which also forms a contactsurface, likewise runs.

To mount the plug on the board 2, the plug 1 is so placed on the board 2that the contact surfaces of the connecting elements 8 and the innerconductor 5 rest upon the upper surface of the board 2 and can besoldered thereto. The solder locations on the contact surfaces of theconnecting elements 8 form the ground connection of the plug 1.

As is especially visible from FIG. 4, the board 2, upon which the plug 1is mounted, has a rectangular cutout 9 which opens at the front edge ofthe board 2. The plug 1 is seated on the board 2 from above so that therear segment of the base body 3 lies in the cutout 9. Since theconnecting elements 8 only project laterally from the outer wall of thebase body 3 in the region of the rear segment, these connecting elements8, when the rear segment lies in the cutout 9, rest with their entiresurfaces on the board 2. The rear edges of the connecting elements 8thus terminate flush with the edge of the board 2. The cutout 9 ismatched to the shape of the front segment so that it is received withoutplay in the cutout 9. In this manner an exact positioning of the plug 1on the printed circuit board 2 is ensured. Since the plug 1 is itselfrecessed in the cutout 9, it only occupies a small amount of space.

As is especially visible from FIGS. 2 and 3, positioning pins 10 projectfrom the undersides of the connecting elements 8. Upon setting of theplug 1 on the board 2, the positioning pins 10 pass through holes in theboard 2. This gives rise to an improved positioning precision of theplug 1 on the board 2 and in addition to a position stabilizer of theplug 1.

Basically the connecting elements 8 should extend far enough beyond theback side of the base body 3 that the center of gravity of the plug 1lies upon the board 2 and thus ensures that the plug 1 can be securedagainst tilting relative to the board 2.

In the present case, the lengths of the connecting elements 8 can beshorter so that they alone cannot ensure a secure retention of the plugon the board 2.

For further stabilization of the plug 1 on the board 2, shoulders 11 areprovided which are arranged on opposite sides of the outer wall of thebase body 3.

As will be apparent from FIGS. 2 and 3, the shoulders 11 lie flush withfaces of the connecting elements 8. The shoulders 11 can thus formhorizontally extending bearing surfaces by means of which the shoulders11 rest upon the board 2 from above. The bearing surfaces lie in theconnection plane in which the contact surfaces of the connectingelements 8 also lie. As can be seen from FIGS. 2 and 3, the bearingsurfaces extend directly into the associated contact surfaces.

As can be seen from FIG. 3, the base body 3 has a substantially hollowcylindrical shape. The wall thickness of the base body 3 in the regionabove the connection plane is somewhat larger than in the region belowthe connection plane. Thus the portion of the base body 3 lying abovethe connection plane forms a cylindrical element whose outer diameter islarger than that of the cylindrical element which forms the portion ofthe base body 3 below the connection plane. The bounding surfacesbetween these two portions form the shoulders 11 with their planarbearing surfaces.

For position stabilization of the plug 1, the shoulders 11 lie upon theedges of the board 2. In the simplest case, the shoulders 11 of the basebody 3 rest upon the same board 2 upon which the connecting elements 8of the base body 3 also lie and to which the plug 1 is fastened. In thiscase the cutout 9 and the board 2 are so dimensioned that the bearingsurfaces of the shoulders 11 lie along their edges.

In an especially advantageous embodiment, the shoulders 11 lie upon asecond board 2 a. This case has been illustrated in FIGS. 3 and 4.

The second board 2 a is connected to the front edge of the first board 2at which the cutout 9 for receiving the rear segment of the base body 3opens. At the front edge of the second board 2 a, additional boardmaterial is connected and is joined with the second board 2 a along anintentional-break line S.

Additional board material is in the form of two mutually parallel lugs12, 12 a. Between the lugs 12, 12 a lies an intervening space whosewidth is matched to that of the cutout 9 of the first board 2 and formsan extension of this cutout 9. The total length of the intervening spaceand the cutout 9 matches the total length of the plug 1.

To mount the plug, the plug is seated from above on the first board 2 sothat its connecting element 8 rests upon the board 2 and the shoulders11 lie upon the edges of the first board 2 in the rear segments of thelatter bounding the cutout 9. The front regions of the shoulders 11which are connected to the rear segment rest upon the lugs 12, 12 a ofthe additional board material. As a consequence the plug 1 is supportedover the entire length of the shoulders 11 and the connecting elements 8on supporting surfaces. The plug especially, is thereby secured againstundesired tipping.

After the solder connection between the connecting elements 8 and theinternal conductor 5 of the plug 1 on the one hand and the first board 2on the other, the multiple use is separated and the individual boardsare disconnected from one another. The additional board material isremoved from the thus separated second board 2 a along the intentionalbreak line S.

1. In combination with a printed-circuit board formed at a front edgewith a cutout, a coaxial plug comprising: a base body fitted in thecutout and formed with a pair of shoulders bearing flatly on the boardat edges of the cutout; and a pair of wing-shaped connecting elementsprojecting oppositely from the body and lying flatly on the boardadjacent the edges of the cutout, whereby the elements can be solderedto the board to fix the base body in the cutout.
 2. The plug/boardcombination defined in claim 1, further comprising: an internalconductor extending in and insulated from the base body.
 3. Theplug/board combination defined in claim 2 wherein the conductor isconcentric to the base body and extends longitudinally therepast.
 4. Theplug/board combination defined in claim 1 wherein the shoulders arecoplanar with each other and with faces of the connecting elements. 5.The plug/board combination defined in claim 1 wherein the connectingelements are identical.
 6. The plug/board combination defined in claim 1wherein the connecting elements extend longitudinally past a rear end ofthe base body.
 7. The plug/board combination defined in claim 1 whereinthe base body is formed to each side of the cutout underneath therespective connecting element with a hole and the connecting elementseach have a stabilizing pin fitted to the respective hole.
 8. Theplug/board combination defined in claim 1 further comprising soldersecuring the shoulders and faces of the connecting elements to theboard.
 9. The plug/board combination defined in claim 1 wherein the basebody is tubular.
 10. The plug/board combination defined in claim 9wherein the base body is to one side of the shoulders ofpart-cylindrical shape with a predetermined large diameter of curvatureand is to the other side of the shoulders of part-cylindrical shape witha predetermined small diameter of curvature.
 11. The plug/boardcombination defined in claim 1, further comprising a second boardcoplanar with and spaced from the first-mentioned board, the shoulderslying also on the second board.
 12. The plug/board combination definedin claim 11 wherein the boards are joined at a weakened line traversingthe shoulders, whereby the second board can be broken off the firstboard at the weakened line to leave the body on the first board.
 13. Theplug/board combination defined in claim 11 wherein the second board hasa pair of lugs flanking the body.
 14. The plug/board combination definedin claim 1 wherein the body is formed with a recess adapted to fit witha mounting tool.